The invention relates to a press cylinder.
Presses have a plurality of cylinders into which electrically drivable or electrically operable devices are integrated. Examples which may be mentioned here are the folding jaw cylinder of a press folding unit, into which electrically drivable or operable folding jaws are integrated. As a further example, mention may be made of a plate cylinder of a printing unit of a press, it being possible for electrically drivable or electrically operable clamping devices for printing plates to be integrated into such plate cylinders.
In order to drive or operate the devices integrated into the press cylinder, electrical energy or an electric current is needed, which is generated by a generator assigned to the respective press cylinder. According to the prior art, the electric current generated by the generator is introduced into the rotating press cylinder via slip rings in order to be able to operate the drivable devices with the current introduced in this way. However, the introduction of current into rotating press cylinders via slip rings has the disadvantage that the slip rings are susceptible, and therefore the reliability of the folding jaws or pins is not ensured. The introduction of current into rotating press cylinders via slip rings is accordingly disadvantageous overall.
On this basis, the present invention is based on the problem of providing a novel type of press cylinder.
According to the invention, a generator housing of the generator is permanently connected to the press cylinder and rotates with the same, a generator rotor belonging to the generator and enclosed by the generator housing rotating relative to the generator housing and it being possible for the generator rotor to be driven by an electric motor.
In the sense of the present invention, it is provided to connect the generator housing of the generator permanently to the rotating press cylinder, so that the generator housing rotates together with the press cylinder. As a result of the rigid connection of the generator housing to the press cylinder, the current generated by the generator can be introduced into the rotating press cylinder without any difficulty. There is no relative movement between the generator housing and the press cylinder, so that it is possible to dispense with components moved relative to one other in order to introduce current into the press cylinder. This increases the reliability of the introduction of current into the press cylinder and the generator has to be serviced less frequently.
The rotational speed of the electric motor and therefore of the generator rotor can preferably be matched to the rotational speed of the press cylinder in such a way that the generator generates an electric current with a constant frequency.
According to an advantageous development of the present invention, at least one closed-loop or open-loop control device for the, or each, drivable device that is integrated into the press cylinder is integrated into the press cylinder, the, or each, closed-loop or open-loop control device being supplied with electrical energy by the generator, and the, or each, closed-loop or open-loop control device integrated into the press cylinder exchanging data without contact with a closed-loop or open-loop control device of other press cylinders or with a central closed-loop or open-loop control device.